Direction of Arrival Estimation Using Compact MIMO Array for Portbale Devices

Accurate direction of arrival (DOA) estimation attracts more intention for smart devices in wireless communication. However, designing compact antenna array for estimation with high accuracy is challenging. In this work, a closely packed MIMO array is particularly designed for proper amplitude ratio over different angles. Combining with the phase information, the accuracy and robustness of the estimation is improved, with phase ambiguity eliminated as well. Simulation results show that the proposed MIMO array obtains a maximum and averaged RMS error of 2 degrees and less than 1 degree, respectively, over the entire azimuth plane with an SNR of 10 dB. It performs well at both high and low SNR scenarios, and can be easily integrated in devices such as Wi-Fi router.